1. Field of the Invention
This invention generally relates to electronic maps, and in particular to electronic maps displayed on an optical output unit of a navigation system onboard a vehicle. More particularly, the invention relates to a method of displaying an object on an electronic map as well as a storage unit for storing objects to be displayed on an electronic map and a navigation system including such a storage unit.
2. Related Art
Navigation systems having optical output units, e.g., in the form of a monitor or other display unit, are widely known. Such optical output devices frequently serve to display a portion of a map in order to facilitate information transfer to a user, e.g., a driver of a vehicle, and the provision of driving directions to the user. To improve recognition quality, objects other than roads are frequently also displayed on the optical output unit. Traffic signs, e.g., direction signs and vegetation, e.g., trees, are examples of objects that are displayed on electronic maps of navigation systems. An optical appearance or graphical representation of these objects is frequently stored in a so-called “style database”, which stores the full graphical representations of the object to be displayed, e.g., in the form of any suitable graphic data format. This form of storing data related to various objects in the style database allows instances of the respective objects to be readily generated on the electronic map, without much additional processing by a processing unit.
Storage of this type of data in a style database has several disadvantages. For example, different end users frequently desire the same object to be displayed in various different designs. Since many graphical data formats cannot be easily modified so as to accommodate such different designs, frequently, different style databases have to be provided for different end users. A further drawback of several known systems for displaying an object on an electronic map is that if a new object type is introduced or an existing object type is modified, substantial modifications of the style database and/or of the software on which the navigation system operates may be required to appropriately adapt the system to display the new or modified object type.
Therefore, a continued need exists for methods and systems for displaying objects on an electronic map. In particular, there exists a need for a method and system for displaying an object on an electronic map, e.g., in a navigation device, into which new objects can be easily integrated and in which a single database may be used for different end users, while still allowing these different end users to easily integrate their individual design options.